The FTC, however, will not take further action against the banks because the five-year statute of limitations has run out, Tsuyoshi Okumura, a senior investigator for the International Antitrust Investigation Bureau, told a media briefing.

The antitrust watchdog accused the banks of exchanging information and agreeing prices on U.S. dollar bonds issued by an international organisation. It did not identify the Japanese bank.

Last year, Deutsche Bank and Bank of America agreed to pay a combined $65.5 million to settle investor litigation accusing large banks of rigging the roughly $9 trillion market for U.S. government agency bonds. (Reporting by Junko Fujita and Takahiko Wada; Editing by Chris Gallagher)